Trade networks were the routes that connected markets in different cities, called. Hence, option C is correct.What is Trade networks?A system of trade-friendly roads or routes of Trade is one way to spread products that are in high demand. Unit 3 examined the trade networks in the Indian Ocean, Mediterranean Sea, Sahara, and Arabian Peninsula.Between the middle of the 2nd millennium BCE and the beginning of the Common Era, communities in Southeast Asia, Western Asia, the Mediterranean, China, and the Indian subcontinent developed extensive transit networks for trade. Building trade networks required the development of roadways, which frequently saw high traffic volumes. Along with transporting goods, people also exchanged ideas, religious practices, and occasionally even sicknesses over these roads.Thus, option C is correct.